1. Field of the Invention
The present invention relates to a toner cartridge used for supplying toner to a developing unit of an image forming apparatus, and more particularly to a cartridge of the throwaway type which is used by being attached to a toner supply unit of an image forming apparatus.
2. Related Art
In a conventional toner supply device for supplying toner to a developing unit of a copying machine, a toner box is installed in a main body of the copying machine. Toner is supplied from the toner box to the developing unit by means of an auger. When toner is used up in the toner box, the toner box is pulled out to a toner supply position, and toner contained in a spare toner bottle is supplied to the toner box. In the toner supply work, toner tends to scatter and stain user's hands, clothes, and the like therewith. The kinds of toner supplied are different for the types of the copying machines used. These facts make user's toner supply work difficult and complicated. For this reason, the toner supply work is usually done by a serviceman.
In the copying machine thus arranged for the toner supply, the user must call a serviceman every time toner is used up. This is troublesome for the user. Further, if the serviceman arrives, toner is not always quickly supplied to the machine. This is time consuming and use of the copying machine is almost impossible till the toner supply work is completed. The result is inefficient use of the copying machine.
Further, in the toner supply work, the user often experiences that leaked toner drops on the floor on which the machine is located, or sticks to clothes. There is a proposal that a cartridge filled with toner is used in place of the conventional toner bottle. In the copying machine using the cartridge, when loaded to the machine, the cartridge is set to the toner box, and a cap is removed from the cartridge, and then toner is supplied. After the toner supply is completed, the cartridge is removed from the machine. The proposal succeeded in lessening such a chance that the leaked toner drop on the floor or sticks to the clothes.
The toner supply work for the machine using the cartridge requires at least three actions; 1) to set the cartridge to the toner box, 2) to supply toner to the toner box, and 3) to remove the cartridge. This is troublesome work. The serviceman call is still needed for the toner supply work. Accordingly, as in the case using the toner bottle, when toner is used up, the user must call a serviceman, and much time is taken till the serviceman comes and he completes the toner supply. Further, when the cartridge is removed after toner is supplied, toner tends to leak and stain user's clothes therewith.